The goal of this proposal is to correlate the hemodynamic BOLD signal with cellular electrophysiological activity in the human medial temporal lobes. This project proposes to perform high-resolution structural imaging studies of the hippocampal area during performance of navigation tasks. Using computational methods that allow unfolding of activity in subregions of the brain, I will examine fMRI BOLD activity in the subnuclei of the hippocampus and specific layers of the parahippoccampal region. These same patients will subsequently be implanted with depth electrodes in these brain regions as part of resection planning for treatment of pharmacologically intractable epilepsy. Using an 128 channel recording system that allows continuous sampling of wide band electrophysiological data, both EEG and single neuron responses in the hippocampal area will be examined. By examining EEG and single neuron responses to behaviorally relevant events, these signals will then be correlated with the BOLD signal. Testing with control subjects will provide insight into which activations in patients may represent impairments due to seizures and can justify comparing our findings on correlations between BOLD and electrophysiology to normal brain activity. [unreadable] [unreadable]